Character guide

Colonel Candido Mariano da Silva Rondon

major

Also known as Colonel Rondon, Rondon

Rondon is the expedition's Brazilian spine: a sertanista who knows the backcountry, its peoples, and its rivers, and whose name Roosevelt inscribes with the words 'Gallant Officer, High-Minded Gentleman, and Intrepid Explorer.' His authority rests on discipline and self-effacement — he reads Thomas à Kempis on deck while others skin jaguars — and on a lifetime of pushing lines through country that resists them. His partnership with Roosevelt sets the expedition's tone: two stubborn men of very different nations bound by the same appetite for the unmapped.

Kermit Roosevelt

major

Also known as Kermit

Kermit enters the narrative in southern Brazil, fresh off a steel span that collapsed under him and left him with two broken ribs and a dislocated knee. He is not there as a president's son on display; he squats on the deck over a paddle-wheel finishing jaguar skins alongside Cherrie and Miller. His presence gives the expedition a family stake and a younger generation's grit, and it quietly raises the cost of every hazard the river will later present.

Theodore Roosevelt

major

Also known as Colonel Roosevelt, the colonel

Roosevelt opens the book not with a summons to adventure but with a lunch at the American Museum of Natural History, where Father Zahm turns up unannounced and the Paraguay scheme revives. He frames the journey as science — naturalists, specimens, a collecting trip for the museum — but his real appetite is for the interior, the unmapped river, the test. As narrator and leader he is both host and protagonist, and his voice sets the book's double register: genial, curious, and unflinching about hardship.

George K. Cherrie

supporting

Also known as Cherrie, Mrs. Cherrie, Messrs. George K. Cherrie

Cherrie is the expedition's most seasoned field man, an Iowa-born Vermont farmer whose wife once camped with him on the Orinoco and whose second child was born two hundred miles from the nearest white settlement. His past includes three months in a South American prison expecting daily to be shot, and two and a half years as a gunrunner — after which he named a new ant-thrush for the revolutionary chief he had served. That blend of ornithology and insurrection makes him exactly the kind of companion Roosevelt trusts in country where the map runs out.

Leo E. Miller

supporting

Also known as Miller, Leo Miller

Miller arrives at Barbados from the Guiana forests, a young naturalist whose enthusiasm and writing both recommend him. On the river he and Cherrie trap tayras, opossums, and other small mammals, and he becomes the special protector of a tame little owl that signals for him when he enters the cabin. His work is the expedition's scientific counterweight to its physical ordeal, and his partnership with Cherrie gives the collecting its method and its small domestic tendernesses.

Lieutenant João Lyra

supporting

Also known as Lieutenant Lyra, Lyra, João

Lyra belongs to Rondon's cadre of Brazilian officers — Amilcar, Mello, Lauriadó, and the doctor Cajazeira among them — whose surveying and discipline make the expedition possible. Roosevelt inscribes the book to them as 'Companions in Scientific Work and in the Exploration of the Wilderness,' placing them beside Rondon in his esteem. Their presence makes the journey a joint Brazilian-American enterprise rather than a presidential excursion, and their local knowledge is the quiet infrastructure beneath every mile the party gains.

Anthony Fiala

supporting

Also known as Fiala, Mr. Fiala

Fiala is the expedition's quartermaster and photographer, a man whose quarter-century of arduous wilderness travel has taught him exactly what a party needs and how little of it they can carry. When Rondon inspected the assembled supplies at Corumbá, he could suggest nothing — a quiet vindication for a man who had never before set foot in the tropics. His competence frees the expedition to leave civilization behind, making him the unglamorous hinge on which the whole journey turns.

Father Zahm

supporting

Father Zahm is Roosevelt's old crony — a fellow lover of Dante, history, and science — whose 1908 visit planted the seed of the whole adventure. When Roosevelt finally committed to the trip, Zahm had already decided to go himself, arriving at the museum lunch with his own plans and a naturalist in mind. His presence gives the expedition its origin story and a scholarly, companionable thread through the early chapters.

Julio

supporting

Julio belongs to the expedition's working backbone — the men who handle boats, meals, and the unglamorous labor that keeps a party alive. His Brazilian background places him between Roosevelt's American naturalists and the river itself, a practical counterweight to the scientific ambitions around him. As the journey shifts from steamer to canoe, his role grows quietly essential to the story's middle arc.

John D. Haseman

supporting

Also known as Haseman, Mr. Haseman

Haseman is one of the museum men Roosevelt recruited to make the journey a collecting trip rather than a mere tour. His work — seining, preserving, cataloguing — gives the expedition a scientific purpose beyond adventure, and his findings feed Roosevelt's fascination with piranhas, insects, and the teeming life of tropical waters. He represents the quieter, methodical strand of the enterprise that runs alongside its dangers.

Captain Amilcar de Magalhães

supporting

Also known as Captain Amilcar, Amilcar

Captain Amilcar is one of Colonel Rondon's trusted officers, lent to the expedition as both soldier and engineer. His training in mapping and river work makes him indispensable once the party leaves charted routes behind, and his presence signals Brazil's serious stake in the enterprise. Roosevelt names him among the companions he esteems, and his competence quietly underwrites the expedition's most dangerous stretches.

Antonio the Indian

supporting

Also known as Antonio, the Indian

Antonio belongs to the small corps of local men whose skills the expedition depends on once it enters the interior. His familiarity with the water, the forest, and the routines of river travel places him at the practical frontier between Roosevelt's party and the land they are crossing. As the journey narrows to canoes and unknown channels, his presence becomes one of the quiet conditions of survival.

Cartucho

minor

Brazilian boatman on the River of Doubt.

Jacob Sigg

minor

Also known as Sigg

Swiss naturalist and taxidermist on the expedition.

Paishon

minor

Indigenous Parecís guide and interpreter.

Senhor Caripe

minor

Brazilian rancher who hosted the expedition.

Simplicio

minor

Also known as Poor Simplicio

Brazilian boatman who drowned on the River of Doubt.

Lieutenant Joaquin de Mello Filho

minor

Also known as Lieutenant Mello, Mello

Brazilian army officer on the expedition.

Doctor Vital Brazil

minor

Also known as Doctor Brazil

Brazilian physician and snakebite researcher met during the journey.

Lieutenant Pyrineus

minor

Also known as Pyrineus

Brazilian army officer assisting the expedition.

Benedetto

minor

Italian-born boatman on the expedition.

Lobo

minor

Brazilian boatman on the expedition.

Doctor Euzebio de Oliveira

minor

Also known as Euzebio Oliveira, Oliveira

Brazilian geologist who assisted the expedition.

Elwin R. Sanborn

minor

Naturalist and bird collector on the expedition.

Luiz

minor

Brazilian cook and camp assistant on the expedition.

Antonio Correa

minor

Brazilian boatman on the River of Doubt.

Trigueiro

minor

Also known as Good Trigueiro

Brazilian boatman on the expedition.

Doctor Cajazeira

minor

Brazilian physician met during the journey.

Lieutenant Lauriadó

minor

Also known as Lauriadó

Brazilian army officer on the expedition.

Pedrinho Craveiro

minor

Also known as Pedrinho

Brazilian boatman on the River of Doubt.